Received: (at 78735) by debbugs.gnu.org; 9 Jun 2025 20:09:01 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Mon Jun 09 16:09:01 2025
Received: from localhost ([127.0.0.1]:57952 helo=debbugs.gnu.org)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
id 1uOinj-0007wK-8F
for submit <at> debbugs.gnu.org; Mon, 09 Jun 2025 16:09:01 -0400
Received: from mail-4316.protonmail.ch ([185.70.43.16]:18513)
by debbugs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
(Exim 4.84_2) (envelope-from <pipcet@HIDDEN>)
id 1uOinW-0007tJ-Ds
for 78735 <at> debbugs.gnu.org; Mon, 09 Jun 2025 16:08:48 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com;
s=protonmail3; t=1749499719; x=1749758919;
bh=LcV6dj3b4bvrxMz2HnEViXRvk6F++crDnwNMLQ9CcCQ=;
h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References:
Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID:
Message-ID:BIMI-Selector:List-Unsubscribe:List-Unsubscribe-Post;
b=KDXlYaIVQbWEFX7i1k823HmsyGB+OS+NYs+OA+YE/N1rar64ihaiVxeLQqAF5zofP
doOYKeH2rO75F9EIaNubgAZr23D0dXDyYgfDylDvPLF+eYT/+bBXWm6M1KL3PTC2tZ
JVX2Zyl4aCiYu2s84SJQBYN2InwIeY4rDaHrjEUg2rVZCtBFsk5KGDNpP+Ma017hLe
AgAHNmu2YowytHaKIfN1YpWxndTw0Og9qCnoW7aOPJyVMnWtjT5bh9Xtb8NjOnFnYj
ep6FkFjf2fWNa3IFS5g1td3aIM8lwbeqtMAWiIn0FxJdX1dpovVgeU1JAUionM4eES
LlG1dK59cS5xg==
Date: Mon, 09 Jun 2025 20:08:36 +0000
To: Helmut Eller <eller.helmut@HIDDEN>
From: Pip Cet <pipcet@HIDDEN>
Subject: Re: bug#78735: feature/igc: [PATCH] Reduce the size of the kbd-buffer
GC root
Message-ID: <87y0u03cg0.fsf@HIDDEN>
In-Reply-To: <87v7p4g10y.fsf@HIDDEN>
References: <87v7p4g10y.fsf@HIDDEN>
Feedback-ID: 112775352:user:proton
X-Pm-Message-ID: cb1733aa83d308e01d9e937e36763256985794af
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
X-Spam-Score: 0.0 (/)
X-Debbugs-Envelope-To: 78735
Cc: 78735 <at> debbugs.gnu.org
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -1.0 (-)
"Helmut Eller" <eller.helmut@HIDDEN> writes:
> This is a proposal to reduce of the size of the kbd-buffer root.
> Currently the kdb-buffer is an area of ~250kb that is scanned
> ambiguously.
>
> With the patch, instead of tracing the entire kbd_buffer, we only scan
> the region from kbd_fetch_ptr - 1 to kbd_store_ptr + 1. The -1/+1 is
> supposed to cover the cases where MPS stops the mutator while those
> pointers are being updated. If the kbd_buffer is empty, then only 180
> bytes are scanned. It's still scanned ambiguously.
That sounds great to me.
> +static union buffered_input_event *
> +prev_kbd_event (union buffered_input_event *kbd_buffer,
> +=09=09union buffered_input_event *ptr)
> +{
> + return ptr =3D=3D kbd_buffer ? kbd_buffer + KBD_BUFFER_SIZE - 1 : ptr =
- 1;
> +}
> +
> +static union buffered_input_event *
> +next_kbd_event (union buffered_input_event *kbd_buffer,
> +=09=09union buffered_input_event *ptr)
> +{
> + return ptr =3D=3D kbd_buffer + KBD_BUFFER_SIZE - 1 ? kbd_buffer : ptr =
+ 1;
> +}
Just out of curiosity, is there a reason for the extra kbd_buffer
argument? Since this code is replicated a few times, maybe it would be
better to keep next_kbd_event in keyboard.c identical to the one in
igc.c. Maybe not, though...
> + union buffered_input_event *fetch
> + =3D prev_kbd_event (kbd_buffer, kbd_fetch_ptr);
> + union buffered_input_event *store
> + =3D next_kbd_event (kbd_buffer, kbd_store_ptr);
> +
> + if (fetch < store)
> + return scan_ambig (ss, fetch, store, closure);
I think this will fail if kbd_store_ptr + 1 =3D=3D kbd_fetch_ptr (i.e. the
kbd_buffer is full)?
if (fetch < store - 1)
should work, though, and it's not like this case is common enough to
worry about scanning the same event twice.
Pip
bug-gnu-emacs@HIDDEN:bug#78735; Package emacs.
Full text available.
Received: (at submit) by debbugs.gnu.org; 9 Jun 2025 19:37:09 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Mon Jun 09 15:37:09 2025
Received: from localhost ([127.0.0.1]:57750 helo=debbugs.gnu.org)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
id 1uOiIu-0002Y5-8d
for submit <at> debbugs.gnu.org; Mon, 09 Jun 2025 15:37:09 -0400
Received: from lists.gnu.org ([2001:470:142::17]:57994)
by debbugs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
(Exim 4.84_2) (envelope-from <eller.helmut@HIDDEN>)
id 1uOiIq-0002Vm-Qj
for submit <at> debbugs.gnu.org; Mon, 09 Jun 2025 15:37:05 -0400
Received: from eggs.gnu.org ([2001:470:142:3::10])
by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
(Exim 4.90_1) (envelope-from <eller.helmut@HIDDEN>)
id 1uOiId-0006ug-QI
for bug-gnu-emacs@HIDDEN; Mon, 09 Jun 2025 15:36:51 -0400
Received: from mail-wm1-x334.google.com ([2a00:1450:4864:20::334])
by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128)
(Exim 4.90_1) (envelope-from <eller.helmut@HIDDEN>)
id 1uOiIb-000456-Nc
for bug-gnu-emacs@HIDDEN; Mon, 09 Jun 2025 15:36:51 -0400
Received: by mail-wm1-x334.google.com with SMTP id
5b1f17b1804b1-441ab63a415so48644295e9.3
for <bug-gnu-emacs@HIDDEN>; Mon, 09 Jun 2025 12:36:48 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=20230601; t=1749497807; x=1750102607; darn=gnu.org;
h=mime-version:user-agent:message-id:date:subject:to:from:from:to:cc
:subject:date:message-id:reply-to;
bh=FxrgLnE6VyxDp7YZaNOj10PNt3a9fh4QtFMflRtFl+Y=;
b=kwv7xAbQb1tJ2RzWxDMp0tz2C1ywsRAO/LYpDxWt5MjQhuDHelpSGo2M0vRhEjhHiO
q71rK3zO7lQrUzu3m5egikjZLXpq3OUqW7uZBiH1WqIm+iiRuD0HQLEW6gAQ2C9z2fn0
hLIL+xU6CJPb2evKiid56DoUnmFs6YkSqqqLYK13IldYEt5q2HvEfdUZgkw/rJFH8Gqb
rOYV7XVv7OgCUMI7JN6hxBlfLaF61GQxgNddCQSErqQqhE69pI/TN2bKqV/XUl7VbLhU
FvYbgKOK0DNXXuoKFtVwCfS9gwbIhXUQOiLHJogwVSvbXSOPAWn7C5i5U8TvUV2scAzP
6ZAw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20230601; t=1749497807; x=1750102607;
h=mime-version:user-agent:message-id:date:subject:to:from
:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to;
bh=FxrgLnE6VyxDp7YZaNOj10PNt3a9fh4QtFMflRtFl+Y=;
b=fWH5TR3c8c4WScYY5XRncIIKWWay8AFrX8nT8B8MqYxEPHZd3xd36f1ELd3DIbJCD1
n6LkTJXHRA1yNqR2kYdNLCxtdRGKZ7qMcbOm+XBV3MNkSv29/rgmZ9gp85YxLzqcbfJX
GiNK7KIaYGzwQ+wUDM/RQdrj0C+42fS/FoF4LfUObK7/e7NBb0cNo9lrfhb9awiHw/WS
5BADZslX3oIgnDkmhPveksvkinCOKZcJlZPHHFt7FOn5X8qG87gkF2qx5MbiSKR0TPQv
NkZOepgp3EKixZIcBTDrvhcGfrzweEwm/8iesFU6CTeiPmjymQq1TOkkof3QVq7bd5Yy
+8Xw==
X-Gm-Message-State: AOJu0Yy34sUG2PKsPxvFPtMwJLdwklIhWTZPfZ6fzvlYbGBIQhHEjGQT
Qf4RxpRs9XQggYePeC8d/vKRLZaN+0UluJHeI2cVEFgubFegHI62mZlxDa8rlw==
X-Gm-Gg: ASbGncuOiw80tBqlCCqiz22fD+O3K82LNsQ+52qzum7jhk0nB26Jhe/WZOFTDsp9qrv
rw9waVdJNDNahBJ7UhKonr3B7B5DcXrncqXFPA0QbR+XLy1kJ/6nvDisc44ja5VBz6ewuKawjOM
dDGmVWl/dy82N0iLEwo++sEEG6vyMPj4YCYOZBnv2Nbg9EUYbDSYZq4H0MKWY218vTerPo6u8ED
kvhULCo3tGYGTwPHQlsuOxNtA8WNVDAVn0Y+BDWggKKfzd7TAwJxCB5sMAPSXghHzQSJBIQ7TYi
iwvGXZETi7jlts/OMiXIX5o+p9Dpro7apXVC6RtjFcdC1bcfqRmjyhi8NN5K+oo9ECmuY3QUghD
hIl2tCsEf3xm/FprjgLM=
X-Google-Smtp-Source: AGHT+IENANJWap2bniZjwCdeKI0ctruYBKr6Pe2rU2GkMrOxDG47Xj1TWO9pxAzBTb+Fz4wntIrChA==
X-Received: by 2002:a05:600c:1c95:b0:453:a95:f07d with SMTP id
5b1f17b1804b1-4531de05552mr220105e9.10.1749497806732;
Mon, 09 Jun 2025 12:36:46 -0700 (PDT)
Received: from caladan (dial-184179.pool.broadband44.net. [212.46.184.179])
by smtp.gmail.com with ESMTPSA id
5b1f17b1804b1-4526e0563b6sm117527515e9.7.2025.06.09.12.36.45
for <bug-gnu-emacs@HIDDEN>
(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
Mon, 09 Jun 2025 12:36:45 -0700 (PDT)
From: Helmut Eller <eller.helmut@HIDDEN>
To: bug-gnu-emacs@HIDDEN
Subject: feature/igc: [PATCH] Reduce the size of the kbd-buffer GC root
X-Debbugs-Cc:
Date: Mon, 09 Jun 2025 21:36:45 +0200
Message-ID: <87v7p4g10y.fsf@HIDDEN>
User-Agent: Gnus/5.13 (Gnus v5.13)
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="=-=-="
Received-SPF: pass client-ip=2a00:1450:4864:20::334;
envelope-from=eller.helmut@HIDDEN; helo=mail-wm1-x334.google.com
X-Spam_score_int: -20
X-Spam_score: -2.1
X-Spam_bar: --
X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,
DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001,
RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001,
SPF_PASS=-0.001 autolearn=ham autolearn_force=no
X-Spam_action: no action
X-Spam-Score: 1.0 (+)
X-Debbugs-Envelope-To: submit
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -0.0 (/)
--=-=-=
Content-Type: text/plain
This is a proposal to reduce of the size of the kbd-buffer root.
Currently the kdb-buffer is an area of ~250kb that is scanned
ambiguously.
With the patch, instead of tracing the entire kbd_buffer, we only scan
the region from kbd_fetch_ptr - 1 to kbd_store_ptr + 1. The -1/+1 is
supposed to cover the cases where MPS stops the mutator while those
pointers are being updated. If the kbd_buffer is empty, then only 180
bytes are scanned. It's still scanned ambiguously.
--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
filename=0001-Reduce-the-size-of-the-kbd-buffer-GC-root.patch
From d1e9eeb7d3cfea48d1037564fda50b511e80a52b Mon Sep 17 00:00:00 2001
From: Helmut Eller <eller.helmut@HIDDEN>
Date: Mon, 9 Jun 2025 18:28:10 +0200
Subject: [PATCH] Reduce the size of the kbd-buffer GC root
* src/igc.c (root_create_kbd_buffer): New.
(root_create_main_thread): Use it.
(scan_kbd_buffer_ambig): New. The actual scan function.
(next_kbd_event, prev_kbd_event): New helpers, similar to next_kbd_event
in keyboard.c.
* src/keyboard.c (init_keyboard): Move the GC root creation code to
root_create_kbd_buffer in igc.c.
---
src/igc.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++
src/keyboard.c | 4 ----
2 files changed, 52 insertions(+), 4 deletions(-)
diff --git a/src/igc.c b/src/igc.c
index f63b0fe8c88..5f7a1a78cda 100644
--- a/src/igc.c
+++ b/src/igc.c
@@ -60,6 +60,7 @@
#include "thread.h"
#include "treesit.h"
#include "termchar.h"
+#include "keyboard.h"
#ifdef HAVE_WINDOW_SYSTEM
#include TERM_HEADER
#endif /* HAVE_WINDOW_SYSTEM */
@@ -1725,6 +1726,48 @@ scan_tty_list (mps_ss_t ss, void *start, void *end, void *closure)
return MPS_RES_OK;
}
+static union buffered_input_event *
+prev_kbd_event (union buffered_input_event *kbd_buffer,
+ union buffered_input_event *ptr)
+{
+ return ptr == kbd_buffer ? kbd_buffer + KBD_BUFFER_SIZE - 1 : ptr - 1;
+}
+
+static union buffered_input_event *
+next_kbd_event (union buffered_input_event *kbd_buffer,
+ union buffered_input_event *ptr)
+{
+ return ptr == kbd_buffer + KBD_BUFFER_SIZE - 1 ? kbd_buffer : ptr + 1;
+}
+
+static mps_res_t
+scan_kbd_buffer_ambig (mps_ss_t ss, void *start, void *end, void *closure)
+{
+ igc_assert (start == kbd_buffer);
+ igc_assert (end == kbd_buffer + ARRAYELTS (kbd_buffer));
+
+ /* Instead of tracing the entire kbd_buffer, only scan the region from
+ kbd_fetch_ptr - 1 to kbd_store_ptr + 1. The -1/+1 is supposed to
+ cover the cases where MPS stops the mutator while those pointers
+ are being updated. */
+
+ union buffered_input_event *fetch
+ = prev_kbd_event (kbd_buffer, kbd_fetch_ptr);
+ union buffered_input_event *store
+ = next_kbd_event (kbd_buffer, kbd_store_ptr);
+
+ if (fetch < store)
+ return scan_ambig (ss, fetch, store, closure);
+ else
+ {
+ mps_res_t res
+ = scan_ambig (ss, fetch, kbd_buffer + KBD_BUFFER_SIZE, closure);
+ if (res == MPS_RES_OK)
+ res = scan_ambig (ss, kbd_buffer, store, closure);
+ return res;
+ }
+}
+
/***********************************************************************
Default pad, fwd, ...
***********************************************************************/
@@ -2905,6 +2948,14 @@ root_create_tty_list (struct igc *gc)
scan_tty_list, "tty-list");
}
+static void
+root_create_kbd_buffer (struct igc *gc)
+{
+ root_create (gc, kbd_buffer, kbd_buffer + ARRAYELTS (kbd_buffer),
+ mps_rank_ambig (), scan_kbd_buffer_ambig, NULL,
+ true, "kbd-buffer");
+}
+
static void
root_create_main_thread (struct igc *gc)
{
@@ -4934,6 +4985,7 @@ make_igc (void)
root_create_main_thread (gc);
root_create_exact_ptr (gc, ¤t_thread);
root_create_exact_ptr (gc, &all_threads);
+ root_create_kbd_buffer (gc);
enable_messages (gc, true);
return gc;
diff --git a/src/keyboard.c b/src/keyboard.c
index 72c6e4c17d8..1c2b4ba9e63 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -12892,10 +12892,6 @@ delete_kboard (KBOARD *kb)
void
init_keyboard (void)
{
-#ifdef HAVE_MPS
- igc_root_create_ambig (kbd_buffer, kbd_buffer + ARRAYELTS (kbd_buffer),
- "kbd-buffer");
-#endif
/* This is correct before outermost invocation of the editor loop. */
command_loop_level = -1;
quit_char = Ctl ('g');
--
2.39.5
--=-=-=--
Helmut Eller <eller.helmut@HIDDEN>:bug-gnu-emacs@HIDDEN.
Full text available.bug-gnu-emacs@HIDDEN:bug#78735; Package emacs.
Full text available.
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997 nCipher Corporation Ltd,
1994-97 Ian Jackson.